EN ISO 8434-1:2018
(Main)Metallic tube connections for fluid power and general use - Part 1: 24° cone connectors (ISO 8434-1:2018, Corrected version 2018-10)
Metallic tube connections for fluid power and general use - Part 1: 24° cone connectors (ISO 8434-1:2018, Corrected version 2018-10)
This document specifies the general and dimensional requirements for 24° cone connectors using cutting ring and O‑ring seal cone (referred to as DKO) suitable for use with ferrous and non‑ferrous tubes with outside diameters from 4 mm to 42 mm inclusive. These connectors are for use in fluid power and general applications within the limits of pressure and temperature specified in this document.
They are intended for the connection of plain end tubes and hose fittings to ports in accordance with ISO 6149‑1, ISO 1179‑1 and ISO 9974‑1. (See ISO 12151‑2 for a related hose fitting specification.)
These connectors provide full-flow connections in hydraulic systems operating to the working pressures shown in Table 1. Because many factors influence the pressure at which a system performs satisfactorily, these values are not intended to be understood as guaranteed minimums. For every application, sufficient testing is meant to be conducted and reviewed by both the user and manufacturer to ensure that required performance levels are met.
NOTE 1 For new designs in hydraulic fluid power applications, see the requirements given in 9.6. Where the requirements of the application allow for the use of elastomeric seals, connector designs that conform to International Standards and incorporate elastomeric sealing are preferred.
NOTE 2 For use under conditions outside the pressure and/or temperature limits specified, see 5.4.
This document also specifies a performance and qualification test for these connectors.
Metallische Rohrverschraubungen für Fluidtechnik und allgemeine Anwendung - Teil 1: Verschraubungen mit 24°-Konus (ISO 8434-1:2018)
Dieses Dokument legt allgemeine und maßliche Anforderungen an 24°-Rohrverschraubungen mit Schneid-ring und O-Ring-Dichtkegel (kurz als DKO bezeichnet) fest, die für die Verwendung mit Stahlrohren und Rohren aus Nicht-Eisenmetallen mit einem Außendurchmesser von 4 mm bis einschließlich 42 mm geeignet sind. Diese Rohrverschraubungen sind für die Fluidtechnik und allgemeine Anwendungen im festgelegten Temperatur- und Druckbereich nach diesem Dokument vorgesehen.
Sie sind für die Verbindung von Rohren mit geraden Enden und Schlaucharmaturen an Einschraublöchern nach ISO 6149-1, ISO 1179-1 und ISO 9974-1 vorgesehen. (Festlegungen für Schlaucharmaturen, siehe ISO 12151-2.)
Diese Rohrverschraubungen sorgen in Hydraulikanlagen mit Arbeitsdrücken nach Tabelle 1 für Verbin-dungen mit vollem Durchfluss. Da der Druck, bei dem eine Anlage zufriedenstellend funktionsfähig ist, durch viele Faktoren beeinflusst wird, sind diese Werte nicht als abgesicherte Mindestwerte zu betrachten. Für jeden Anwendungsfall müssen ausreichende Prüfungen durchgeführt werden, die sowohl vom Anwender als auch vom Hersteller zu bewerten sind, um sicherzustellen, dass die geforderten Leistungsstufen eingehalten werden.
ANMERKUNG 1 Für Neukonstruktionen in hydraulischen Anlagen der Fluidtechnik gelten die Anforderungen in 9.6. Sofern nach den Anforderungen für den jeweiligen Anwendungsfall die Verwendung von Elastomerdichtungen zulässig ist, werden für die Rohrverschraubung Ausführungen nach Internationalen Normen mit Elastomerdichtungen bevor-zugt.
ANMERKUNG 2 Für Anwendungsfälle außerhalb des in dieser Norm festgelegten Druck- und/oder Temperatur-bereichs, siehe 5.4.
Dieses Dokument legt ferner eine Prüfung der Funktionsfähigkeit und Eignung dieser Rohrverschraubungen fest.
Raccordements de tubes métalliques pour transmissions hydrauliques et pneumatiques et applications générales - Partie 1: Raccords coniques à 24° (ISO 8434-1:2018, Version corrigée 2018-10)
Le présent document spécifie les exigences générales et dimensionnelles relatives à la conception et à la performance des raccords à compression à 24°, utilisant une bague de compression et un cône à joint torique (désigné comme DKO) qui sont adaptés à l'utilisation avec des tubes en métaux ferreux et non ferreux de diamètre extérieur de 4 mm à 42 mm inclus. Ces raccords sont utilisés dans les transmissions hydrauliques et pneumatiques et les applications générales dans les limites de pression et de température spécifiées dans le présent document.
Ils sont prévus pour le raccordement de tubes et de tuyaux à des orifices conformes à l'ISO 6149‑1, l'ISO 1179‑1 et l'ISO 9974‑1. (Voir l'ISO 12151‑2 pour les spécifications relatives aux raccordements flexibles.)
Ces raccords fournissent des connexions pleins débits dans des transmissions hydrauliques fonctionnant à des pressions d'utilisation telles que montrées dans le Tableau 1. À cause de l'influence de nombreux facteurs sur la pression à laquelle le système fonctionne de manière satisfaisante, ces valeurs ne sont pas destinées à être considérées comme des minima garantis. Pour chaque application, des essais suffisants sont à réaliser et à examiner à la fois par l'utilisateur et le fabricant, afin de s'assurer que le niveau de performance requis est atteint.
NOTE 1 Pour les nouvelles conceptions pour des applications de transmissions hydrauliques, voir les exigences données en 9.6. Dans les cas où les exigences de l'application permettent l'utilisation de joints en élastomères, la conception des raccords doit se conformer aux Normes internationales et incorporer de préférence des joints élastomères.
NOTE 2 Pour des utilisations en dehors des limites de températures et/ou de pressions spécifiées, voir 5.4.
Le présent document décrit également un essai de performance et de qualification relatif à ces raccords.
Kovinski cevni priključki za fluidno tehniko in za splošno uporabo - 1. del: Stožčasti priključki z naklonom 24° (ISO 8434-1:2018, popravljena različica 2018-10)
Ta dokument določa splošne in dimenzijske zahteve za stožčaste priključke z naklonom 24° z uporabo rezalnega obroča ter O-obročnega tesnilnega stožca (DKO), primernega za uporabo z železnimi in neželeznimi cevmi z zunanjimi premeri od 4 mm do vključno 42 mm. Ti priključki so namenjeni uporabi v fluidni tehniki ter splošnih načinih uporabe znotraj mejnih vrednosti tlaka in temperature, določenih v tem dokumentu.
Namenjeni so za priključitev navadnih končnih cevi in priključkov cevi v vrata v skladu s standardi ISO 6149-1, ISO 1179-1 in ISO 9974-1 (za ustrezne cevne fitinge glej ISO 12151-2). Ti priključki tvorijo priključke za poln pretok v hidravličnih sistemih, ki delujejo pri vrednostih delovnega tlaka, prikazanih v preglednici 1. Ker številni dejavniki vplivajo na tlak, pri katerem sistem deluje zadovoljivo, te vrednosti ne pomenijo zajamčenih minimalnih vrednosti. Za vsak način uporabe je treba opraviti ustrezno preskušanje, ki ga morata pregledati tako uporabnik kot proizvajalec, da zagotovita izpolnitev zahtevanih ravni zmogljivosti.
OPOMBA 1: Za uporabo novih modelov v fluidni tehniki glej zahteve, podane v točki 9.6. Kadar zahteve načina uporabe dovoljujejo uporabo elastomernih tesnil, imajo prednost modeli priključkov, ki so v skladu z mednarodnimi standardi in zagotavljajo elastomerno tesnjenje.
OPOMBA 2: Za uporabo pod pogoji zunaj določenih mejnih vrednosti tlaka in/ali temperature glej točko 5.4.
Ta dokument za te priključke določa tudi zmogljivostni in kvalifikacijski preskus.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-november-2018
Nadomešča:
SIST EN ISO 8434-1:2007
SIST EN ISO 8434-1:2007/AC:2009
Kovinski cevni priključki za fluidno tehniko in za splošno uporabo - 1. del:
Stožčasti priključki z naklonom 24° (ISO 8434-1:2018, popravljena različica 2018-
10)
Metallic tube connections for fluid power and general use - Part 1: 24° cone connectors
(ISO 8434-1:2018, Corrected version 2018-10)
Metallische Rohrverschraubungen für Fluidtechnik und allgemeine Anwendung - Teil 1:
Verschraubungen mit 24°-Konus (ISO 8434-1:2018, korrigierte Fassung 2018-10)
Raccordements de tubes métalliques pour transmissions hydrauliques et pneumatiques
et applications générales - Partie 1: Raccords coniques à 24° (ISO 8434-1:2018, Version
corrigée 2018-10)
Ta slovenski standard je istoveten z: EN ISO 8434-1:2018
ICS:
23.100.40 Cevna napeljava in sklopke Piping and couplings
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN ISO 8434-1
EUROPEAN STANDARD
NORME EUROPÉENNE
August 2018
EUROPÄISCHE NORM
ICS 23.100.40 Supersedes EN ISO 8434-1:2007
English Version
Metallic tube connections for fluid power and general use -
Part 1: 24° cone connectors (ISO 8434-1:2018, Corrected
version 2018-10)
Raccordements de tubes métalliques pour Metallische Rohrverschraubungen für Fluidtechnik
transmissions hydrauliques et pneumatiques et und allgemeine Anwendung - Teil 1: Verschraubungen
applications générales - Partie 1: Raccords coniques à mit 24°-Konus (ISO 8434-1:2018)
24° (ISO 8434-1:2018, Version corrigée 2018-10)
This European Standard was approved by CEN on 4 July 2018.
This European Standard was corrected and reissued by the CEN-CENELEC Management Centre on 19 December 2018.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATIO N
EUROPÄISCHES KOMITEE FÜR NORMUN G
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 8434-1:2018 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
European foreword
This document (EN ISO 8434-1:2018) has been prepared by Technical Committee ISO/TC 131 "Fluid
power systems" in collaboration with Technical Committee ECISS/TC 110 “Steel tubes, and iron and
steel fittings” the secretariat of which is held by UNI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by February 2019, and conflicting national standards
shall be withdrawn at the latest by February 2019.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 8434-1:2007.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 8434-1:2018, Corrected version 2018-10 has been approved by CEN as EN ISO 8434-
1:2018 without any modification.
INTERNATIONAL ISO
STANDARD 8434-1
Third edition
2018-07
Corrected version
2018-10
Metallic tube connections for fluid
power and general use —
Part 1:
24° cone connectors
Raccordements de tubes métalliques pour transmissions hydrauliques
et pneumatiques et applications générales —
Partie 1: Raccords coniques à 24°
Reference number
ISO 8434-1:2018(E)
©
ISO 2018
ISO 8434-1:2018(E)
© ISO 2018
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
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Published in Switzerland
ii © ISO 2018 – All rights reserved
ISO 8434-1:2018(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Materials . 3
4.1 General . 3
4.2 Connector bodies . 4
4.3 Nuts . 4
4.4 Cutting rings . 5
4.5 O-rings . 5
5 Pressure/temperature requirements . 5
6 Designation of connectors . 9
7 Requirements for tubes .12
8 Across‑flats dimensions and tolerances .12
9 Design .12
9.1 Connectors .12
9.2 Dimensions .12
9.3 Passage tolerances .13
9.4 Angular tolerances .13
9.5 Contour details .13
9.6 Ports and stud ends .13
9.7 Stud end sealing .13
10 Screw threads .13
10.1 Cone ends and nuts .13
10.2 Stud ends (connection ends) .13
11 Manufacture .13
11.1 Construction .13
11.2 Workmanship .14
11.3 Finish .14
11.4 Corners .14
12 Assembly instruction .14
13 Procurement information .15
14 Marking of components .15
15 Performance and qualification test .15
15.1 General .15
15.2 Repeated assembly test .15
15.3 Proof test .15
15.4 Burst pressure test .15
15.5 Cyclic endurance (impulse) test .15
15.6 Vibration test .15
15.7 Leakage (gas) test .16
15.8 Overtightening test .16
15.8.1 Connectors with cutting rings .16
15.8.2 Connectors with O-ring seal cone (DKO) .16
15.9 Vacuum test .16
16 Identification statement (reference to this document) .16
ISO 8434-1:2018(E)
Annex A (normative) Assembly instructions for 24° cone connectors using cutting ring
conforming to ISO 8434‑1 .45
Bibliography .51
iv © ISO 2018 – All rights reserved
ISO 8434-1:2018(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: www .iso .org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 131, Fluid power systems, Subcommittee
SC 4, Connectors and similar products and components.
This third edition cancels and replaces the second edition (ISO 8434-1:2007), which has been technically
revised.
A list of all the parts in the ISO 8434 series, can be found on the ISO website.
This corrected version of ISO 8434-1:2018 incorporates the following corrections:
— Table 4: missing data in the Thread column of Series L and S has been inserted.
— Table 21: missing data in the s column of Series L and S has been inserted.
ISO 8434-1:2018(E)
Introduction
In fluid power systems, power is transmitted and controlled through a fluid (liquid or gas) under
pressure within an enclosed circuit. In general applications, a fluid may be conveyed under pressure.
Components may be connected through their ports by connections (connectors) and conductors (tubes
and hoses). Tubes are rigid conductors; hoses are flexible conductors.
vi © ISO 2018 – All rights reserved
INTERNATIONAL STANDARD ISO 8434-1:2018(E)
Metallic tube connections for fluid power and general use —
Part 1:
24° cone connectors
1 Scope
This document specifies the general and dimensional requirements for 24° cone connectors using
cutting ring and O-ring seal cone (referred to as DKO) suitable for use with ferrous and non-ferrous
tubes with outside diameters from 4 mm to 42 mm inclusive. These connectors are for use in fluid power
and general applications within the limits of pressure and temperature specified in this document.
They are intended for the connection of plain end tubes and hose fittings to ports in accordance with
ISO 6149-1, ISO 1179-1 and ISO 9974-1. (See ISO 12151-2 for a related hose fitting specification.)
These connectors provide full-flow connections in hydraulic systems operating to the working
pressures shown in Table 1. Because many factors influence the pressure at which a system performs
satisfactorily, these values are not intended to be understood as guaranteed minimums. For every
application, sufficient testing is meant to be conducted and reviewed by both the user and manufacturer
to ensure that required performance levels are met.
NOTE 1 For new designs in hydraulic fluid power applications, see the requirements given in 9.6. Where
the requirements of the application allow for the use of elastomeric seals, connector designs that conform to
International Standards and incorporate elastomeric sealing are preferred.
NOTE 2 For use under conditions outside the pressure and/or temperature limits specified, see 5.4.
This document also specifies a performance and qualification test for these connectors.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 48, Rubber, vulcanized or thermoplastic — Determination of hardness (hardness between 10 IRHD and
100 IRHD)
ISO 228-1, Pipe threads where pressure-tight joints are not made on the threads — Part 1: Dimensions,
tolerances and designation
ISO 724, ISO general-purpose metric screw threads — Basic dimensions
ISO 965-1, ISO general purpose metric screw threads — Tolerances — Part 1: Principles and basic data
ISO 1127, Stainless steel tubes — Dimensions, tolerances and conventional masses per unit length
ISO 1179-1, Connections for general use and fluid power — Ports and stud ends with ISO 228-1 threads with
elastomeric or metal-to-metal sealing — Part 1: Threaded ports
ISO 1179-2, Connections for general use and fluid power — Ports and stud ends with ISO 228-1 threads with
elastomeric or metal-to-metal sealing — Part 2: Heavy-duty (S series) and light-duty (L series) stud ends
with elastomeric sealing (type E)
ISO 8434-1:2018(E)
ISO 1179-4, Connections for general use and fluid power — Ports and stud ends with ISO 228-1 threads
with elastomeric or metal-to-metal sealing — Part 4: Stud ends for general use only with metal-to-metal
sealing (type B)
ISO 3304, Plain end seamless precision steel tubes — Technical conditions for delivery
ISO 3305, Plain end welded precision steel tubes — Technical conditions for delivery
ISO 3601-3, Fluid power systems — O-rings — Part 3: Quality acceptance criteria
ISO 4759-1:2000, Tolerances for fasteners — Part 1: Bolts, screws, studs and nuts — Product grades A, B and C
ISO 5598:2008, Fluid power systems and components — Vocabulary
ISO 6149-1, Connections for hydraulic fluid power and general use — Ports and stud ends with ISO 261
metric threads and O-ring sealing — Part 1: Ports with truncated housing for O-ring seal
ISO 6149-2, Connections for hydraulic fluid power and general use — Ports and stud ends with ISO 261
metric threads and O-ring sealing — Part 2: Dimensions, design, test methods and requirements for heavy-
duty (S series) stud ends
ISO 6149-3, Connections for hydraulic fluid power and general use — Ports and stud ends with ISO 261
metric threads and O-ring sealing — Part 3: Dimensions, design, test methods and requirements for light-
duty (L series) stud ends
ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests
ISO 9974-1, Connections for general use and fluid power — Ports and stud ends with ISO 261 threads with
elastomeric or metal-to-metal sealing — Part 1: Threaded ports
ISO 9974-2, Connections for general use and fluid power — Ports and stud ends with ISO 261 threads with
elastomeric or metal-to-metal sealing — Part 2: Stud ends with elastomeric sealing (type E)
ISO 9974-3, Connections for general use and fluid power — Ports and stud ends with ISO 261 threads with
elastomeric or metal-to-metal sealing — Part 3: Stud ends with metal-to-metal sealing (type B)
ISO 19879, Metallic tube connections for fluid power and general use — Test methods for hydraulic fluid
power connections
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5598 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http: //www .electropedia .org/
— ISO Online browsing platform: available at http: //www .iso .org/obp
3.1
connector
device that connects tubes, hoses or pipes to each other or to components
[SOURCE: ISO 5598:2008, 3.2.122]
3.2
connection
assembly of parts belonging to piping
3.3
fastening thread
terminal thread of a complete connector
2 © ISO 2018 – All rights reserved
ISO 8434-1:2018(E)
3.4
run
two principal, axially aligned outlets of a tee connector or cross connector
[SOURCE: ISO 5598:2008, 3.2.632]
3.5
branch
side outlet(s) of a tee connector or cross connector
[SOURCE: ISO 5598:2008, 3.2.81]
3.6
chamfer
removal of a conical portion at the entrance of a thread, used to assist assembly and prevent damage to
the start of the thread
3.7
face‑to‑face dimension
distance between the two parallel faces of axially aligned outlets of a connector
3.8
face‑to‑centre dimension
distance from the face of an outlet to the central axis of an angularly disposed outlet
3.9
assembly torque
torque required to achieve a satisfactory final connection
[SOURCE: ISO 5598:2008, 3.2.46]
3.10
maximum working pressure
highest pressure at which a system or sub-system is intended to operate in steady-state operating
conditions
Note 1 to entry: For components and piping see also related term “rated pressure”.
[SOURCE: ISO 5598:2008, 3.2.429, modified — NOTE 2 deleted.]
4 Materials
4.1 General
Figures 1 and 2 show the cross-sections and component parts of typical 24° cone connectors.
ISO 8434-1:2018(E)
Key
1 body
2 nut
3 cutting ring
Figure 1 — Cross‑section of typical 24° cone connector with cutting ring
Key
1 body
2 nut
3 DKO-end (including O-ring)
Figure 2 — Cross‑section of typical 24° cone connector with O‑ring seal cone (DKO) end
4.2 Connector bodies
Bodies shall be manufactured from carbon steel that will provide the minimum pressure/temperature
requirements specified in Clause 5. They shall have characteristics that make them suitable for use
with the fluid to be conveyed and that will provide an effective joint. Weld connector types and weld-on
nipples shall be made of materials classified as suitable for welding.
For bodies manufactured from stainless steel and copper alloys, the pressure/temperature ratings
need to be defined by the manufacturer.
4.3 Nuts
Nuts to be used with carbon steel bodies shall be made of carbon steel, and those for use with stainless
steel bodies shall be made of stainless steel, unless otherwise specified. Nuts to be used with copper
alloy bodies shall be made of a material similar to the bodies.
4 © ISO 2018 – All rights reserved
ISO 8434-1:2018(E)
4.4 Cutting rings
4.4.1 The ring material shall be compatible with the fluid to be conveyed and provide an effective joint.
4.4.2 Steel cutting rings are to be used in combination with other steel connector components and
steel tubes.
4.4.3 Stainless steel cutting rings are to be used in combination with other stainless steel connector
components and stainless steel tubes.
4.4.4 Brass cutting rings are to be used in combination with other brass connector components and
copper tubes.
4.4.5 Other combinations of materials shall be agreed upon between the purchaser and supplier.
4.5 O‑rings
Unless otherwise specified, for use with petroleum-based hydraulic fluids at the pressure and
temperature requirements given in Clause 5 and Table 1, O-rings for use with connectors in accordance
with this document shall be made of acrylonitrile-butadiene rubber (NBR) with a hardness of
(90 ± 5) IRHD, measured in accordance with ISO 48, and shall conform to the dimensions given in
Table 7 and shall meet or exceed the O-ring quality acceptance criteria of ISO 3601-3, grade N. In those
cases where the pressure and temperature requirements of this document and/or the hydraulic fluid
used in the system differ from those specified in Clause 5 and Table 1, the connector manufacturer shall
be consulted to ensure that an appropriate O-ring material is selected.
5 Pressure/temperature requirements
5.1 Connectors in conformance with this document made of carbon steel shall meet or exceed
without leakage the requirements from a vacuum of 6,5 kPa (0,065 bar) absolute pressure to the
working pressures given in Tables 1 to 3 when used at temperatures between −40 °C and +120 °C with
petroleum-base hydraulic fluids.
5.2 Connectors conforming to this document can contain elastomeric seals. Unless otherwise
specified, connectors are made and delivered with elastomeric seals for use within the specified working
temperature range with petroleum-base hydraulic fluids. The use of these connectors and elastomeric
seals with other hydraulic fluids may result in a reduced working temperature range or may render the
connectors unsuitable for the application. Manufacturers may supply, upon request, connectors with
elastomeric seals for use with hydraulic fluids other than petroleum-base hydraulic fluids which will
meet the specified working temperature range of the connectors.
5.3 The connector assembly shall meet or exceed all applicable performance requirements given in
Clause 15. Testing shall be conducted at room temperature.
5.4 For applications under conditions other than the pressure and/or temperature limits given in
Tables 1 to 3 and in 5.1 and 5.3, the manufacturer shall be consulted.
5.5 According to different applications and different pressure ratings, there are three series of
connector, designated by
— LL, for extra light-duty,
— L, for light-duty, and
— S, for heavy-duty.
ISO 8434-1:2018(E)
NOTE Ranges of the tube outside diameters and pressure requirements are shown in Tables 1 to 3.
Table 1 — Working pressures for 24° cone connectors for fluid power and general use
Tube outside Cone and cutting ring connection ISO 6149‑2 or ISO 6149‑3 stud end
diameter (OD)
Maximum working Maximum working
a a
pressure pressure
Series
Thread Thread
b b
MPa (bar ) MPa (bar )
mm
4 M8 × 1 10 (100) — — —
5 M10 × 1 10 (100) — — —
LL
6 M10 × 1 10 (100) — — —
8 M12 × 1 10 (100) — — —
6 M12 × 1,5 25 (250) M10 × 1 25 (250)
8 M14 × 1,5 25 (250) M12 × 1,5 25 (250)
10 M16 × 1,5 25 (250) M14 × 1,5 25 (250)
12 M18 × 1,5 25 (250) M16 × 1,5 25 (250)
15 M22 × 1,5 25 (250) M18 × 1,5 25 (250)
L
18 M26 × 1,5 16 (160) M22 × 1,5 16 (160)
22 M30 × 2 16 (160) M27 × 2 16 (160)
28 M36 × 2 10 (100) M33 × 2 10 (100)
35 M45 × 2 10 (100) M42 × 2 10 (100)
42 M52 × 2 10 (100) M48 × 2 10 (100)
6 M14 × 1,5 63 (630) M12 × 1,5 63 (630)
8 M16 × 1,5 63 (630) M14 × 1,5 63 (630)
10 M18 × 1,5 63 (630) M16 × 1,5 63 (630)
12 M20 × 1,5 63 (630) M18 × 1,5 63 (630)
S 16 M24 × 1,5 40 (400) M22 × 1,5 40 (400)
20 M30 × 2 40 (400) M27 × 2 40 (400)
25 M36 × 2 40 (400) M33 × 2 40 (400)
30 M42 × 2 25 (250) M42 × 2 25 (250)
38 M52 × 2 25 (250) M48 × 2 25 (250)
For higher pressure ratings and for dynamic conditions, the manufacturer shall be consulted.
a
With a design factor of 4 to 1.
b 5 2 5
1 bar = 10 N/m = 10 Pa = 0,1 MPa.
6 © ISO 2018 – All rights reserved
ISO 8434-1:2018(E)
Table 2 — Working pressures for 24° cone connectors, for general use only
Cone and cutting ring
Tube OD
ISO 9974 stud end ISO 1179 stud end
connection
a a
Maximum working pressure Maximum working pressure
Maximum
Series
working pres-
ISO 9974-2 ISO 9974-3 ISO 1179-2 ISO 1179-4
Thread Thread Thread
a
sure b c b c
(type E) (type B) (type E) (type B)
mm MPa (bar) MPa (bar) MPa (bar) MPa (bar) MPa (bar)
4 M8 × 1 10 (100) M8 × 1 — — 10 (100) G 1/8 A — — 10 (100)
5 M10 × 1 10 (100) M8 × 1 — — 10 (100) — — — — —
LL
6 M10 × 1 10 (100) M10 × 1 — — 10 (100) — — — — —
8 M12 × 1 10 (100) M10 × 1 — — 10 (100) — — — — —
6 M12 × 1,5 25 (250) M10 × 1 25 (250) 25 (250) G 1/8 A 25 (250) 25 (250)
8 M14 × 1,5 25 (250) M12 × 1,5 25 (250) 25 (250) G 1/4 A 25 (250) 25 (250)
10 M16 × 1,5 25 (250) M14 × 1,5 25 (250) 25 (250) G 1/4 A 25 (250) 25 (250)
12 M18 × 1,5 25 (250) M16 × 1,5 25 (250) 25 (250) G 3/8 A 25 (250) 25 (250)
15 M22 × 1,5 25 (250) M18 × 1,5 25 (250) 25 (250) G 1/2 A 25 (250) 25 (250)
L
18 M26 × 1,5 16 (160) M22 × 1,5 16 (160) 16 (160) G 1/2 A 16 (160) 16 (160)
22 M30 × 2 16 (160) M26 × 1,5 16 (160) 16 (160) G 3/4 A 16 (160) 16 (160)
28 M36 × 2 10 (100) M33 × 2 10 (100) 10 (100) G 1 A 10 (100) 10 (100)
35 M45 × 2 10 (100) M42 × 2 10 (100) 10 (100) G 1 1/4 A 10 (100) 10 (100)
42 M52 × 2 10 (100) M48 × 2 10 (100) 10 (100) G 1 1/2 A 10 (100) 10 (100)
6 M14 × 1,5 63 (630) M12 × 1,5 63 (630) 40 (400) G 1/4 A 63 (630) 40 (400)
8 M16 × 1,5 63 (630) M14 × 1,5 63 (630) 40 (400) G 1/4 A 63 (630) 40 (400)
10 M18 × 1,5 63 (630) M16 × 1,5 63 (630) 40 (400) G 3/8 A 63 (630) 40 (400)
12 M20 × 1,5 63 (630) M18 × 1,5 63 (630) 40 (400) G 3/8 A 63 (630) 40 (400)
S 16 M24 × 1,5 40 (400) M22 × 1,5 40 (400) 40 (400) G 1/2 A 40 (400) 40 (400)
20 M30 × 2 40 (400) M27 × 2 40 (400) 40 (400) G 3/4 A 40 (400) 40 (400)
For higher pressure ratings and for dynamic conditions, the manufacturer shall be consulted.
a
With a design factor of 4 to 1.
b
Type E with elastomeric sealing.
c
Type B with metal-to-metal sealing.
ISO 8434-1:2018(E)
8 © ISO 2018 – All rights reserved
Table 2 (continued)
Cone and cutting ring
Tube OD
ISO 9974 stud end ISO 1179 stud end
connection
a a
Maximum working pressure Maximum working pressure
Maximum
Series
working pres-
ISO 9974-2 ISO 9974-3 ISO 1179-2 ISO 1179-4
Thread Thread Thread
a
sure b c b c
(type E) (type B) (type E) (type B)
mm MPa (bar) MPa (bar) MPa (bar) MPa (bar) MPa (bar)
25 M36 × 2 40 (400) M33 × 2 40 (400) 25 (250) G 1 A 40 (400) 25 (250)
30 M42 × 2 25 (250) M42 × 2 25 (250) 16 (160) G 1 1/4 A 25 (250) 16 (160)
38 M52 × 2 25 (250) M48 × 2 25 (250) 16 (160) G 1 1/2 A 25 (250) 16 (160)
For higher pressure ratings and for dynamic conditions, the manufacturer shall be consulted.
a
With a design factor of 4 to 1.
b
Type E with elastomeric sealing.
c
Type B with metal-to-metal sealing.
ISO 8434-1:2018(E)
Table 3 — Working pressures for 24° cone weld‑on nipples with various tube wall thicknesses
Dimensions in millimetres
Maximum working pressure
10 MPa 16 MPa 25 MPa 31,5 MPa 40 MPa 63 MPa
Tube
Series (100 bar) (160 bar) (250 bar) (315 bar) (400 bar) (630 bar)
OD
Tube Tube Tube Tube Tube Tube
T T T T T T
ID ID ID ID ID ID
6 3 1,5 3 1,5 3 1,5
8 5 1,5 5 1,5 5 1,5
10 7 1,5 7 1,5 7 1,5
12 8 2 8 2 8 2
15 10 2,5 10 2,5 10 2,5
L
18 13 2,5 13 2,5
22 17 2,5 17 2,5
28 23 2,5
35 29 3
42 36 3
6 2,5 1,75 2,5 1,75 2,5 1,75 2,5 1,75 2,5 1,75 2,5 1,75
8 4 2 4 2 4 2 4 2 4 2 4 2
10 6 2 6 2 6 2 6 2 6 2 5 2,5
12 8 2 8 2 8 2 8 2 7 2,5 6 3
S 16 11 2,5 11 2,5 11 2,5 11 2,5 10 3
20 14 3 14 3 14 3 14 3 12 4
25 19 3 19 3 19 3 17 4 16 4,5
30 24 3 24 3 22 4
38 32 3 32 3 28 5
For pressure and/or temperature applications outside those given in this document, the manufacturer shall be consulted.
ID interior diameter
T tube wall thickness
6 Designation of connectors
6.1 Connectors shall be designated by an alphanumeric code to facilitate ordering. They shall be
designated by the word “Connector” followed by ISO 8434-1, followed by a spaced hyphen, then the
connector style letter symbols (see 6.2), followed by a spaced hyphen, then the series letter(s) (see 5.5),
immediately followed by the outside diameter of the tube with which they are to be connected. For weld
nipples, a multiplication sign (×) shall then follow, then the tube wall thickness. There shall be no spaces
on either side of the multiplication symbol. For stud ends (connector ends), a multiplication symbol
followed by the thread designation of the stud end, followed by a spaced hyphen and the sealing type
shall be added.
6.2 The letter symbol designation of the connector style shall have three parts: the connection end
type, immediately followed by the shape of the connector and by the indication that a complete connector
is ordered.
6.3 Tube ends are assumed and thus do not need to be included in the code. However, if another type
of end is involved, it shall be designated.
6.4 Reducing connectors and reducing elbows shall be designated by specifying the larger tube end first.
ISO 8434-1:2018(E)
6.5 Stud connectors (see Figures 3 and 4) shall be designated by specifying the tube end first, then the
thread size for the stud end with the sealing type letter.
6.6 For tee connectors, the order of designation of the connection ends shall start with the larger end
on the run followed by the tee.
6.7 For cross connectors, the order of designation of the connection ends shall be from left to right,
followed by top to bottom, with the larger ends on the left and at the top.
6.8 If the connector has a swivel, it shall be designated first. On run tees the branch end shall follow.
6.9 The following letter symbols shall be used.
Connection end type Symbol
Bulkhead BH
Swivel with O-ring SWO
Weld-on/weld-in WD
Stud SD
Reducer RD
Shape Symbol
Straight S
Elbow E
45° elbow E45
Tee T
Run tee RT
Branch tee BT
Cross K
Component type Symbol
Nut N
Cutting ring CR
Locknut LN
Nipple NP
Plug PL
10 © ISO 2018 – All rights reserved
ISO 8434-1:2018(E)
Completeness indication Symbol
Complete connector C
Stud end sealing types Symbol
Metal-to-metal sealing B
Elastomeric sealing E
O-ring sealing F
6.10 Examples of compression connectors and designations are given below and in Figures 3 to 6.
EXAMPLE 1 A stud straight connector, including O-ring without cutting ring and nut, with a heavy-duty stud
connection end having an M18 × 1,5 thread in accordance with ISO 6149-2, to be connected to a 12 mm OD tube,
is designated for ordering as follows:
Connector ISO 8434-1 - SDS - S12×M18 - F
Figure 3 — Stud straight connector (SDS) with stud end as per ISO 6149‑2 (sealing type F)
EXAMPLE 2 A complete stud straight connector, including O-ring with cutting ring and nut, with a heavy-duty
stud connection end having an M18 × 1,5 thread in accordance with ISO 6149-2, to be connected to a 12 mm OD
tube, is designated for ordering as follows:
Connector ISO 8434-1 - SDSC - S12×M18 - F
Figure 4 — Complete stud straight connector (SDSC) with stud end as per ISO 6149-2
(sealing type F)
EXAMPLE 3 A complete weld-on nipple, including O-ring, with a light-duty connection end, to be welded to a
15 mm OD tube having a wall thickness of 1,5 mm, is designated for ordering as follows:
Connector ISO 8434‑1 ‑ WDNP ‑ L15×1,5
Figure 5 — Weld‑on nipple with O‑ring (WDNP)
ISO 8434-1:2018(E)
EXAMPLE 4 A branch tee reducer connector with a swivel with O-Ring union connector (DKO) to be connected
to an 18 mm OD tube end on the branch and to be connected with 15 mm OD tubes on the run, is designated for
ordering as follows:
Connector ISO 8434‑1 ‑ SWOBT ‑ L18 ‑ L15 ‑ L15
Figure 6 — Branch tee (SWOBT) reducer with O‑Ring
7 Requirements for tubes
Carbon steel tubes shall comply with delivery condition R37 NBK, as specified in ISO 3304 (cold-drawn
and normalized) or ISO 3305 (cold-drawn and normalized). Stainless steel tubes shall be in accordance
with ISO 1127 (annealed).
8 Across‑flats dimensions and tolerances
8.1 For sizes up to and including 24 mm, tolerances for across-flats dimensions for forgings shall be
0 0
mm, and for sizes larger than 24 mm, they shall be mm.
−08, −1
8.2 Hex tolerances across flats shall be in accordance with ISO 4759-1, product grade C. Minimum
across-corner hex dimensions are 1,092 times the width across flats. The minimum side flat is 0,43 times
the nominal width across flats. Unless otherwise specified or shown, hex corners shall be chamfered 10°
to 15° to a diameter equal to the width across flats, with a tolerance of mm. The dimensions across
−04,
flats for nuts and on the bodies of the connectors shall be those given in Table 5 and Tables 9 to 21.
9 Design
9.1 Connectors
The connectors shall conform to the requirements given in Figures 7 to 26 and Tables 4 to 22. They
shall be designed so that resistance to flow is reduced to a minimum.
9.2 Dimensions
Dimensions specified apply to finished parts, including any plating or other treatments. The tolerance
value for all dimensions not otherwise limited shall be ±0,4 mm. The sealing seats of connectors shall
be concentric with straight thread pitch diameters within 0,25 mm full indicator reading (FIR).
12 © ISO 2018 – All rights reserved
ISO 8434-1:2018(E)
9.3 Passage tolerances
Where passages in straight connectors are machined from opposite ends, the offset at the meeting
point shall not exceed 0,4 mm. No cross-sectional area at a junction of passages shall be less than that of
the smallest specified passage.
9.4 Angular tolerances
Angular tolerance on axes of ends of elbows, tees and crosses shall be ±2,5° for connectors for tube
sizes 10 mm and smaller, and ±1,5° for all larger sizes.
9.5 Contour details
Details of contour shall be chosen by the manufacturer provided the dimensions given in Tables 4 to 22
are maintained. Wrench flats on elbows and tees shall conform to the dimensions given in the relevant
tables. Abrupt reduction of a section shall be avoided. Junctions of small external sections and adjoining
sections that are relatively heavy shall be blended by means of ample fillets.
9.6 Ports and stud ends
These connectors shall be used for the connection of plain end tubes and hose connectors to ports
in accordance with ISO 6149-1, ISO 1179-1 or ISO 9974-1. For new designs in hydraulic fluid power
applications, only ports and stud ends in accordance with the relevant parts of ISO 6149 shall be used.
9.7 Stud end sealing
Unless otherwise agreed upon between the supplier and purchaser, seals for stud ends and weld nipples
shall be included in the delivery.
10 Screw threads
10.1 Cone ends and nuts
The screw threads on the cone ends and the nuts of the connectors shall be ISO metric screw threads in
accordance with ISO 724, tolerance grade 6g and 6H respectively, in accordance with ISO 965-1.
Threads shall be chamfered at the face of the connector to an included angle of 45°. The diameter of the
chamfer shall be equal to the minor diameter of the thread, with a tolerance of mm.
−04,
10.2 Stud ends (connection ends)
The thread for stud ends (connection ends) of connectors shall be chosen from ISO 228-1, Class A, or
IS
...
SLOVENSKI STANDARD
01-november-2018
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SIST EN ISO 8434-1:2007
SIST EN ISO 8434-1:2007/AC:2009
.RYLQVNLFHYQLSULNOMXþNL]DIOXLGQRWHKQLNRLQ]DVSORãQRXSRUDERGHO
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Metallic tube connections for fluid power and general use - Part 1: 24° cone connectors
(ISO 8434-1:2018)
Metallische Rohrverschraubungen für Fluidtechnik und allgemeine Anwendung - Teil 1:
Verschraubungen mit 24°-Konus (ISO 8434-1:2018)
Raccordements de tubes métalliques pour transmissions hydrauliques et pneumatiques
et applications générales - Partie 1: Raccords coniques à 24 degrés (ISO 8434-1:2018)
Ta slovenski standard je istoveten z: EN ISO 8434-1:2018
ICS:
23.100.40 Cevna napeljava in sklopke Piping and couplings
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN ISO 8434-1
EUROPEAN STANDARD
NORME EUROPÉENNE
August 2018
EUROPÄISCHE NORM
ICS 23.100.40 Supersedes EN ISO 8434-1:2007
English Version
Metallic tube connections for fluid power and general use -
Part 1: 24° cone connectors (ISO 8434-1:2018)
Raccordements de tubes métalliques pour Metallische Rohrverschraubungen für Fluidtechnik
transmissions hydrauliques et pneumatiques et und allgemeine Anwendung - Teil 1: Verschraubungen
applications générales - Partie 1: Raccords coniques à mit 24°-Konus (ISO 8434-1:2018)
24° (ISO 8434-1:2018)
This European Standard was approved by CEN on 4 July 2018.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 8434-1:2018 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
European foreword
This document (EN ISO 8434-1:2018) has been prepared by Technical Committee ISO/TC 131 "Fluid
power systems" in collaboration with Technical Committee ECISS/TC 110 “Steel tubes, and iron and
steel fittings” the secretariat of which is held by UNI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by February 2019, and conflicting national standards
shall be withdrawn at the latest by February 2019.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 8434-1:2007.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 8434-1:2018 has been approved by CEN as EN ISO 8434-1:2018 without any
modification.
INTERNATIONAL ISO
STANDARD 8434-1
Third edition
2018-07
Metallic tube connections for fluid
power and general use —
Part 1:
24° cone connectors
Raccordements de tubes métalliques pour transmissions hydrauliques
et pneumatiques et applications générales —
Partie 1: Raccords coniques à 24°
Reference number
ISO 8434-1:2018(E)
©
ISO 2018
ISO 8434-1:2018(E)
© ISO 2018
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved
ISO 8434-1:2018(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Materials . 3
4.1 General . 3
4.2 Connector bodies . 4
4.3 Nuts . 4
4.4 Cutting rings . 5
4.5 O-rings . 5
5 Pressure/temperature requirements . 5
6 Designation of connectors . 9
7 Requirements for tubes .12
8 Across‑flats dimensions and tolerances .12
9 Design .12
9.1 Connectors .12
9.2 Dimensions .12
9.3 Passage tolerances .13
9.4 Angular tolerances .13
9.5 Contour details .13
9.6 Ports and stud ends .13
9.7 Stud end sealing .13
10 Screw threads .13
10.1 Cone ends and nuts .13
10.2 Stud ends (connection ends) .13
11 Manufacture .13
11.1 Construction .13
11.2 Workmanship .14
11.3 Finish .14
11.4 Corners .14
12 Assembly instruction .14
13 Procurement information .15
14 Marking of components .15
15 Performance and qualification test .15
15.1 General .15
15.2 Repeated assembly test .15
15.3 Proof test .15
15.4 Burst pressure test .15
15.5 Cyclic endurance (impulse) test .15
15.6 Vibration test .15
15.7 Leakage (gas) test .16
15.8 Overtightening test .16
15.8.1 Connectors with cutting rings .16
15.8.2 Connectors with O-ring seal cone (DKO) .16
15.9 Vacuum test .16
16 Identification statement (reference to this document) .16
ISO 8434-1:2018(E)
Annex A (normative) Assembly instructions for 24° cone connectors using cutting ring
conforming to ISO 8434‑1 .45
Bibliography .51
iv © ISO 2018 – All rights reserved
ISO 8434-1:2018(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: www .iso .org/iso/foreword .html.
This document was prepared by Technical Committee ISO/TC 131, Fluid power systems, Subcommittee
SC 4, Connectors and similar products and components.
This third edition cancels and replaces the second edition (ISO 8434-1:2007), which has been technically
revised.
A list of all the parts in the ISO 8434 series, can be found on the ISO website.
ISO 8434-1:2018(E)
Introduction
In fluid power systems, power is transmitted and controlled through a fluid (liquid or gas) under
pressure within an enclosed circuit. In general applications, a fluid may be conveyed under pressure.
Components may be connected through their ports by connections (connectors) and conductors (tubes
and hoses). Tubes are rigid conductors; hoses are flexible conductors.
vi © ISO 2018 – All rights reserved
INTERNATIONAL STANDARD ISO 8434-1:2018(E)
Metallic tube connections for fluid power and general use —
Part 1:
24° cone connectors
1 Scope
This document specifies the general and dimensional requirements for 24° cone connectors using
cutting ring and O-ring seal cone (referred to as DKO) suitable for use with ferrous and non-ferrous
tubes with outside diameters from 4 mm to 42 mm inclusive. These connectors are for use in fluid power
and general applications within the limits of pressure and temperature specified in this document.
They are intended for the connection of plain end tubes and hose fittings to ports in accordance with
ISO 6149-1, ISO 1179-1 and ISO 9974-1. (See ISO 12151-2 for a related hose fitting specification.)
These connectors provide full-flow connections in hydraulic systems operating to the working
pressures shown in Table 1. Because many factors influence the pressure at which a system performs
satisfactorily, these values are not intended to be understood as guaranteed minimums. For every
application, sufficient testing is meant to be conducted and reviewed by both the user and manufacturer
to ensure that required performance levels are met.
NOTE 1 For new designs in hydraulic fluid power applications, see the requirements given in 9.6. Where
the requirements of the application allow for the use of elastomeric seals, connector designs that conform to
International Standards and incorporate elastomeric sealing are preferred.
NOTE 2 For use under conditions outside the pressure and/or temperature limits specified, see 5.4.
This document also specifies a performance and qualification test for these connectors.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 48, Rubber, vulcanized or thermoplastic — Determination of hardness (hardness between 10 IRHD and
100 IRHD)
ISO 228-1, Pipe threads where pressure-tight joints are not made on the threads — Part 1: Dimensions,
tolerances and designation
ISO 724, ISO general-purpose metric screw threads — Basic dimensions
ISO 965-1, ISO general purpose metric screw threads — Tolerances — Part 1: Principles and basic data
ISO 1127, Stainless steel tubes — Dimensions, tolerances and conventional masses per unit length
ISO 1179-1, Connections for general use and fluid power — Ports and stud ends with ISO 228-1 threads with
elastomeric or metal-to-metal sealing — Part 1: Threaded ports
ISO 1179-2, Connections for general use and fluid power — Ports and stud ends with ISO 228-1 threads with
elastomeric or metal-to-metal sealing — Part 2: Heavy-duty (S series) and light-duty (L series) stud ends
with elastomeric sealing (type E)
ISO 8434-1:2018(E)
ISO 1179-4, Connections for general use and fluid power — Ports and stud ends with ISO 228-1 threads
with elastomeric or metal-to-metal sealing — Part 4: Stud ends for general use only with metal-to-metal
sealing (type B)
ISO 3304, Plain end seamless precision steel tubes — Technical conditions for delivery
ISO 3305, Plain end welded precision steel tubes — Technical conditions for delivery
ISO 3601-3, Fluid power systems — O-rings — Part 3: Quality acceptance criteria
ISO 4759-1:2000, Tolerances for fasteners — Part 1: Bolts, screws, studs and nuts — Product grades A, B and C
ISO 5598:2008, Fluid power systems and components — Vocabulary
ISO 6149-1, Connections for hydraulic fluid power and general use — Ports and stud ends with ISO 261
metric threads and O-ring sealing — Part 1: Ports with truncated housing for O-ring seal
ISO 6149-2, Connections for hydraulic fluid power and general use — Ports and stud ends with ISO 261
metric threads and O-ring sealing — Part 2: Dimensions, design, test methods and requirements for heavy-
duty (S series) stud ends
ISO 6149-3, Connections for hydraulic fluid power and general use — Ports and stud ends with ISO 261
metric threads and O-ring sealing — Part 3: Dimensions, design, test methods and requirements for light-
duty (L series) stud ends
ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests
ISO 9974-1, Connections for general use and fluid power — Ports and stud ends with ISO 261 threads with
elastomeric or metal-to-metal sealing — Part 1: Threaded ports
ISO 9974-2, Connections for general use and fluid power — Ports and stud ends with ISO 261 threads with
elastomeric or metal-to-metal sealing — Part 2: Stud ends with elastomeric sealing (type E)
ISO 9974-3, Connections for general use and fluid power — Ports and stud ends with ISO 261 threads with
elastomeric or metal-to-metal sealing — Part 3: Stud ends with metal-to-metal sealing (type B)
ISO 19879, Metallic tube connections for fluid power and general use — Test methods for hydraulic fluid
power connections
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 5598 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http: //www .electropedia .org/
— ISO Online browsing platform: available at http: //www .iso .org/obp
3.1
connector
device that connects tubes, hoses or pipes to each other or to components
[SOURCE: ISO 5598:2008, 3.2.122]
3.2
connection
assembly of parts belonging to piping
3.3
fastening thread
terminal thread of a complete connector
2 © ISO 2018 – All rights reserved
ISO 8434-1:2018(E)
3.4
run
two principal, axially aligned outlets of a tee connector or cross connector
[SOURCE: ISO 5598:2008, 3.2.632]
3.5
branch
side outlet(s) of a tee connector or cross connector
[SOURCE: ISO 5598:2008, 3.2.81]
3.6
chamfer
removal of a conical portion at the entrance of a thread, used to assist assembly and prevent damage to
the start of the thread
3.7
face‑to‑face dimension
distance between the two parallel faces of axially aligned outlets of a connector
3.8
face‑to‑centre dimension
distance from the face of an outlet to the central axis of an angularly disposed outlet
3.9
assembly torque
torque required to achieve a satisfactory final connection
[SOURCE: ISO 5598:2008, 3.2.46]
3.10
maximum working pressure
highest pressure at which a system or sub-system is intended to operate in steady-state operating
conditions
Note 1 to entry: For components and piping see also related term “rated pressure”.
[SOURCE: ISO 5598:2008, 3.2.429, modified — NOTE 2 deleted.]
4 Materials
4.1 General
Figures 1 and 2 show the cross-sections and component parts of typical 24° cone connectors.
ISO 8434-1:2018(E)
Key
1 body
2 nut
3 cutting ring
Figure 1 — Cross‑section of typical 24° cone connector with cutting ring
Key
1 body
2 nut
3 DKO-end (including O-ring)
Figure 2 — Cross‑section of typical 24° cone connector with O‑ring seal cone (DKO) end
4.2 Connector bodies
Bodies shall be manufactured from carbon steel that will provide the minimum pressure/temperature
requirements specified in Clause 5. They shall have characteristics that make them suitable for use
with the fluid to be conveyed and that will provide an effective joint. Weld connector types and weld-on
nipples shall be made of materials classified as suitable for welding.
For bodies manufactured from stainless steel and copper alloys, the pressure/temperature ratings
need to be defined by the manufacturer.
4.3 Nuts
Nuts to be used with carbon steel bodies shall be made of carbon steel, and those for use with stainless
steel bodies shall be made of stainless steel, unless otherwise specified. Nuts to be used with copper
alloy bodies shall be made of a material similar to the bodies.
4 © ISO 2018 – All rights reserved
ISO 8434-1:2018(E)
4.4 Cutting rings
4.4.1 The ring material shall be compatible with the fluid to be conveyed and provide an effective joint.
4.4.2 Steel cutting rings are to be used in combination with other steel connector components and
steel tubes.
4.4.3 Stainless steel cutting rings are to be used in combination with other stainless steel connector
components and stainless steel tubes.
4.4.4 Brass cutting rings are to be used in combination with other brass connector components and
copper tubes.
4.4.5 Other combinations of materials shall be agreed upon between the purchaser and supplier.
4.5 O‑rings
Unless otherwise specified, for use with petroleum-based hydraulic fluids at the pressure and
temperature requirements given in Clause 5 and Table 1, O-rings for use with connectors in accordance
with this document shall be made of acrylonitrile-butadiene rubber (NBR) with a hardness of
(90 ± 5) IRHD, measured in accordance with ISO 48, and shall conform to the dimensions given in
Table 7 and shall meet or exceed the O-ring quality acceptance criteria of ISO 3601-3, grade N. In those
cases where the pressure and temperature requirements of this document and/or the hydraulic fluid
used in the system differ from those specified in Clause 5 and Table 1, the connector manufacturer shall
be consulted to ensure that an appropriate O-ring material is selected.
5 Pressure/temperature requirements
5.1 Connectors in conformance with this document made of carbon steel shall meet or exceed
without leakage the requirements from a vacuum of 6,5 kPa (0,065 bar) absolute pressure to the
working pressures given in Tables 1 to 3 when used at temperatures between −40 °C and +120 °C with
petroleum-base hydraulic fluids.
5.2 Connectors conforming to this document can contain elastomeric seals. Unless otherwise
specified, connectors are made and delivered with elastomeric seals for use within the specified working
temperature range with petroleum-base hydraulic fluids. The use of these connectors and elastomeric
seals with other hydraulic fluids may result in a reduced working temperature range or may render the
connectors unsuitable for the application. Manufacturers may supply, upon request, connectors with
elastomeric seals for use with hydraulic fluids other than petroleum-base hydraulic fluids which will
meet the specified working temperature range of the connectors.
5.3 The connector assembly shall meet or exceed all applicable performance requirements given in
Clause 15. Testing shall be conducted at room temperature.
5.4 For applications under conditions other than the pressure and/or temperature limits given in
Tables 1 to 3 and in 5.1 and 5.3, the manufacturer shall be consulted.
5.5 According to different applications and different pressure ratings, there are three series of
connector, designated by
— LL, for extra light-duty,
— L, for light-duty, and
— S, for heavy-duty.
ISO 8434-1:2018(E)
NOTE Ranges of the tube outside diameters and pressure requirements are shown in Tables 1 to 3.
Table 1 — Working pressures for 24° cone connectors for fluid power and general use
Tube outside Cone and cutting ring connection ISO 6149‑2 or ISO 6149‑3 stud end
diameter (OD)
Maximum working Maximum working
a a
pressure pressure
Series
Thread Thread
b b
MPa (bar ) MPa (bar )
mm
4 M8 × 1 10 (100) — — —
5 M10 × 1 10 (100) — — —
LL
6 M10 × 1 10 (100) — — —
8 M12 × 1 10 (100) — — —
6 M12 × 1,5 25 (250) M10 × 1 25 (250)
8 M14 × 1,5 25 (250) M12 × 1,5 25 (250)
10 M16 × 1,5 25 (250) M14 × 1,5 25 (250)
12 M18 × 1,5 25 (250) M16 × 1,5 25 (250)
15 M22 × 1,5 25 (250) M18 × 1,5 25 (250)
L
18 M26 × 1,5 16 (160) M22 × 1,5 16 (160)
22 M30 × 2 16 (160) M27 × 2 16 (160)
28 M36 × 2 10 (100) M33 × 2 10 (100)
35 M45 × 2 10 (100) M42 × 2 10 (100)
42 M52 × 2 10 (100) M48 × 2 10 (100)
6 M14 × 1,5 63 (630) M12 × 1,5 63 (630)
8 M16 × 1,5 63 (630) M14 × 1,5 63 (630)
10 M18 × 1,5 63 (630) M16 × 1,5 63 (630)
12 M20 × 1,5 63 (630) M18 × 1,5 63 (630)
S 16 M24 × 1,5 40 (400) M22 × 1,5 40 (400)
20 M30 × 2 40 (400) M27 × 2 40 (400)
25 M36 × 2 40 (400) M33 × 2 40 (400)
30 M42 × 2 25 (250) M42 × 2 25 (250)
38 M52 × 2 25 (250) M48 × 2 25 (250)
For higher pressure ratings and for dynamic conditions, the manufacturer shall be consulted.
a
With a design factor of 4 to 1.
b 5 2 5
1 bar = 10 N/m = 10 Pa = 0,1 MPa.
6 © ISO 2018 – All rights reserved
ISO 8434-1:2018(E)
Table 2 — Working pressures for 24° cone connectors, for general use only
Cone and cutting ring
Tube OD
ISO 9974 stud end ISO 1179 stud end
connection
a a
Maximum working pressure Maximum working pressure
Maximum
Series
working pres-
ISO 9974-2 ISO 9974-3 ISO 1179-2 ISO 1179-4
Thread Thread Thread
a
sure b c b c
(type E) (type B) (type E) (type B)
mm MPa (bar) MPa (bar) MPa (bar) MPa (bar) MPa (bar)
4 M8 × 1 10 (100) M8 × 1 — — 10 (100) G 1/8 A — — 10 (100)
5 M10 × 1 10 (100) M8 × 1 — — 10 (100) — — — — —
LL
6 M10 × 1 10 (100) M10 × 1 — — 10 (100) — — — — —
8 M12 × 1 10 (100) M10 × 1 — — 10 (100) — — — — —
6 M12 × 1,5 25 (250) M10 × 1 25 (250) 25 (250) G 1/8 A 25 (250) 25 (250)
8 M14 × 1,5 25 (250) M12 × 1,5 25 (250) 25 (250) G 1/4 A 25 (250) 25 (250)
10 M16 × 1,5 25 (250) M14 × 1,5 25 (250) 25 (250) G 1/4 A 25 (250) 25 (250)
12 M18 × 1,5 25 (250) M16 × 1,5 25 (250) 25 (250) G 3/8 A 25 (250) 25 (250)
15 M22 × 1,5 25 (250) M18 × 1,5 25 (250) 25 (250) G 1/2 A 25 (250) 25 (250)
L
18 M26 × 1,5 16 (160) M22 × 1,5 16 (160) 16 (160) G 1/2 A 16 (160) 16 (160)
22 M30 × 2 16 (160) M26 × 1,5 16 (160) 16 (160) G 3/4 A 16 (160) 16 (160)
28 M36 × 2 10 (100) M33 × 2 10 (100) 10 (100) G 1 A 10 (100) 10 (100)
35 M45 × 2 10 (100) M42 × 2 10 (100) 10 (100) G 1 1/4 A 10 (100) 10 (100)
42 M52 × 2 10 (100) M48 × 2 10 (100) 10 (100) G 1 1/2 A 10 (100) 10 (100)
6 M14 × 1,5 63 (630) M12 × 1,5 63 (630) 40 (400) G 1/4 A 63 (630) 40 (400)
8 M16 × 1,5 63 (630) M14 × 1,5 63 (630) 40 (400) G 1/4 A 63 (630) 40 (400)
10 M18 × 1,5 63 (630) M16 × 1,5 63 (630) 40 (400) G 3/8 A 63 (630) 40 (400)
12 M20 × 1,5 63 (630) M18 × 1,5 63 (630) 40 (400) G 3/8 A 63 (630) 40 (400)
S 16 M24 × 1,5 40 (400) M22 × 1,5 40 (400) 40 (400) G 1/2 A 40 (400) 40 (400)
20 M30 × 2 40 (400) M27 × 2 40 (400) 40 (400) G 3/4 A 40 (400) 40 (400)
For higher pressure ratings and for dynamic conditions, the manufacturer shall be consulted.
a
With a design factor of 4 to 1.
b
Type E with elastomeric sealing.
c
Type B with metal-to-metal sealing.
ISO 8434-1:2018(E)
8 © ISO 2018 – All rights reserved
Table 2 (continued)
Cone and cutting ring
Tube OD
ISO 9974 stud end ISO 1179 stud end
connection
a a
Maximum working pressure Maximum working pressure
Maximum
Series
working pres-
ISO 9974-2 ISO 9974-3 ISO 1179-2 ISO 1179-4
Thread Thread Thread
a
sure b c b c
(type E) (type B) (type E) (type B)
mm MPa (bar) MPa (bar) MPa (bar) MPa (bar) MPa (bar)
25 M36 × 2 40 (400) M33 × 2 40 (400) 25 (250) G 1 A 40 (400) 25 (250)
30 M42 × 2 25 (250) M42 × 2 25 (250) 16 (160) G 1 1/4 A 25 (250) 16 (160)
38 M52 × 2 25 (250) M48 × 2 25 (250) 16 (160) G 1 1/2 A 25 (250) 16 (160)
For higher pressure ratings and for dynamic conditions, the manufacturer shall be consulted.
a
With a design factor of 4 to 1.
b
Type E with elastomeric sealing.
c
Type B with metal-to-metal sealing.
ISO 8434-1:2018(E)
Table 3 — Working pressures for 24° cone weld‑on nipples with various tube wall thicknesses
Dimensions in millimetres
Maximum working pressure
10 MPa 16 MPa 25 MPa 31,5 MPa 40 MPa 63 MPa
Tube
Series (100 bar) (160 bar) (250 bar) (315 bar) (400 bar) (630 bar)
OD
Tube Tube Tube Tube Tube Tube
T T T T T T
ID ID ID ID ID ID
6 3 1,5 3 1,5 3 1,5
8 5 1,5 5 1,5 5 1,5
10 7 1,5 7 1,5 7 1,5
12 8 2 8 2 8 2
15 10 2,5 10 2,5 10 2,5
L
18 13 2,5 13 2,5
22 17 2,5 17 2,5
28 23 2,5
35 29 3
42 36 3
6 2,5 1,75 2,5 1,75 2,5 1,75 2,5 1,75 2,5 1,75 2,5 1,75
8 4 2 4 2 4 2 4 2 4 2 4 2
10 6 2 6 2 6 2 6 2 6 2 5 2,5
12 8 2 8 2 8 2 8 2 7 2,5 6 3
S 16 11 2,5 11 2,5 11 2,5 11 2,5 10 3
20 14 3 14 3 14 3 14 3 12 4
25 19 3 19 3 19 3 17 4 16 4,5
30 24 3 24 3 22 4
38 32 3 32 3 28 5
For pressure and/or temperature applications outside those given in this document, the manufacturer shall be consulted.
ID interior diameter
T tube wall thickness
6 Designation of connectors
6.1 Connectors shall be designated by an alphanumeric code to facilitate ordering. They shall be
designated by the word “Connector” followed by ISO 8434-1, followed by a spaced hyphen, then the
connector style letter symbols (see 6.2), followed by a spaced hyphen, then the series letter(s) (see 5.5),
immediately followed by the outside diameter of the tube with which they are to be connected. For weld
nipples, a multiplication sign (×) shall then follow, then the tube wall thickness. There shall be no spaces
on either side of the multiplication symbol. For stud ends (connector ends), a multiplication symbol
followed by the thread designation of the stud end, followed by a spaced hyphen and the sealing type
shall be added.
6.2 The letter symbol designation of the connector style shall have three parts: the connection end
type, immediately followed by the shape of the connector and by the indication that a complete connector
is ordered.
6.3 Tube ends are assumed and thus do not need to be included in the code. However, if another type
of end is involved, it shall be designated.
6.4 Reducing connectors and reducing elbows shall be designated by specifying the larger tube end first.
ISO 8434-1:2018(E)
6.5 Stud connectors (see Figures 3 and 4) shall be designated by specifying the tube end first, then the
thread size for the stud end with the sealing type letter.
6.6 For tee connectors, the order of designation of the connection ends shall start with the larger end
on the run followed by the tee.
6.7 For cross connectors, the order of designation of the connection ends shall be from left to right,
followed by top to bottom, with the larger ends on the left and at the top.
6.8 If the connector has a swivel, it shall be designated first. On run tees the branch end shall follow.
6.9 The following letter symbols shall be used.
Connection end type Symbol
Bulkhead BH
Swivel with O-ring SWO
Weld-on/weld-in WD
Stud SD
Reducer RD
Shape Symbol
Straight S
Elbow E
45° elbow E45
Tee T
Run tee RT
Branch tee BT
Cross K
Component type Symbol
Nut N
Cutting ring CR
Locknut LN
Nipple NP
Plug PL
10 © ISO 2018 – All rights reserved
ISO 8434-1:2018(E)
Completeness indication Symbol
Complete connector C
Stud end sealing types Symbol
Metal-to-metal sealing B
Elastomeric sealing E
O-ring sealing F
6.10 Examples of compression connectors and designations are given below and in Figures 3 to 6.
EXAMPLE 1 A stud straight connector, including O-ring without cutting ring and nut, with a heavy-duty stud
connection end having an M18 × 1,5 thread in accordance with ISO 6149-2, to be connected to a 12 mm OD tube,
is designated for ordering as follows:
Connector ISO 8434-1 - SDS - S12×M18 - F
Figure 3 — Stud straight connector (SDS) with stud end as per ISO 6149‑2 (sealing type F)
EXAMPLE 2 A complete stud straight connector, including O-ring with cutting ring and nut, with a heavy-duty
stud connection end having an M18 × 1,5 thread in accordance with ISO 6149-2, to be connected to a 12 mm OD
tube, is designated for ordering as follows:
Connector ISO 8434-1 - SDSC - S12×M18 - F
Figure 4 — Complete stud straight connector (SDSC) with stud end as per ISO 6149-2
(sealing type F)
EXAMPLE 3 A complete weld-on nipple, including O-ring, with a light-duty connection end, to be welded to a
15 mm OD tube having a wall thickness of 1,5 mm, is designated for ordering as follows:
Connector ISO 8434‑1 ‑ WDNP ‑ L15×1,5
Figure 5 — Weld‑on nipple with O‑ring (WDNP)
ISO 8434-1:2018(E)
EXAMPLE 4 A branch tee reducer connector with a swivel with O-Ring union connector (DKO) to be connected
to an 18 mm OD tube end on the branch and to be connected with 15 mm OD tubes on the run, is designated for
ordering as follows:
Connector ISO 8434‑1 ‑ SWOBT ‑ L18 ‑ L15 ‑ L15
Figure 6 — Branch tee (SWOBT) reducer with O‑Ring
7 Requirements for tubes
Carbon steel tubes shall comply with delivery condition R37 NBK, as specified in ISO 3304 (cold-drawn
and normalized) or ISO 3305 (cold-drawn and normalized). Stainless steel tubes shall be in accordance
with ISO 1127 (annealed).
8 Across‑flats dimensions and tolerances
8.1 For sizes up to and including 24 mm, tolerances for across-flats dimensions for forgings shall be
0 0
mm, and for sizes larger than 24 mm, they shall be mm.
−08, −1
8.2 Hex tolerances across flats shall be in accordance with ISO 4759-1, product grade C. Minimum
across-corner hex dimensions are 1,092 times the width across flats. The minimum side flat is 0,43 times
the nominal width across flats. Unless otherwise specified or shown, hex corners shall be chamfered 10°
to 15° to a diameter equal to the width across flats, with a tolerance of mm. The dimensions across
−04,
flats for nuts and on the bodies of the connectors shall be those given in Table 5 and Tables 9 to 21.
9 Design
9.1 Connectors
The connectors shall conform to the requirements given in Figures 7 to 26 and Tables 4 to 22. They
shall be designed so that resistance to flow is reduced to a minimum.
9.2 Dimensions
Dimensions specified apply to finished parts, including any plating or other treatments. The tolerance
value for all dimensions not otherwise limited shall be ±0,4 mm. The sealing seats of connectors shall
be concentric with straight thread pitch diameters within 0,25 mm full indicator reading (FIR).
12 © ISO 2018 – All rights reserved
ISO 8434-1:2018(E)
9.3 Passage tolerances
Where passages in straight connectors are machined from opposite ends, the offset at the meeting
point shall not exceed 0,4 mm. No cross-sectional area at a junction of passages shall be less than that of
the smallest specified passage.
9.4 Angular tolerances
Angular tolerance on axes of ends of elbows, tees and crosses shall be ±2,5° for connectors for tube
sizes 10 mm and smaller, and ±1,5° for all larger sizes.
9.5 Contour details
Details of contour shall be chosen by the manufacturer provided the dimensions given in Tables 4 to 22
are maintained. Wrench flats on elbows and tees shall conform to the dimensions given in the relevant
tables. Abrupt reduction of a section shall be avoided. Junctions of small external sections and adjoining
sections that are relatively heavy shall be blended by means of ample fillets.
9.6 Ports and stud ends
These connectors shall be used for the connection of plain end tubes and hose connectors to ports
in accordance with ISO 6149-1, ISO 1179-1 or ISO 9974-1. For new designs in hydraulic fluid power
applications, only ports and stud ends in accordance with the relevant parts of ISO 6149 shall be used.
9.7 Stud end sealing
Unless otherwise agreed upon between the supplier and purchaser, seals for stud ends and weld nipples
shall be included in the delivery.
10 Screw threads
10.1 Cone ends and nuts
The screw threads on the cone ends and the nuts of the connectors shall be ISO metric screw threads in
accordance with ISO 724, tolerance grade 6g and 6H respectively, in accordance with ISO 965-1.
Threads shall be chamfered at the face of the connector to an included angle of 45°. The diameter of the
chamfer shall be equal to the minor diameter of the thread, with a tolerance of mm.
−04,
10.2 Stud ends (connection ends)
The thread for stud ends (connection ends) of connectors shall be chosen from ISO 228-1, Class A, or
ISO 724, tolerance grade 6g, in accordance with ISO 965-1. The dimensions of the stud ends shall be in
accordance with Tables 11 to 13, 18 and 19 and the relevant stud end standards.
11 Manufacture
11.1 Construction
Carbon steel connectors made from multiple components shall be bonded together with materials
having a melting point of not less than 1 000 °C.
ISO 8434-1:2018(E)
11.2 Workmanship
The connectors shall
...
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